Rotary screening apparatus



Jam 8, 1929.

J. WATT ROTARY SCREENING APPARATUS Filed Feb. 4, 1928 4 Sheets-Sheet lJ. WATT ROTARY SCREENING APPARATUS Filed-Feb.4, 192s 4 Sheets-Sheet 21.,WAT

ROTARY SCREENING APPARMH5 v Jan.- 8, 19.29.

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J. WATT noun SCREENING APPARATUS med Feb. 4, 1928 AShee-ts-Sheet 4Patented Jan. 8, 1929.

JAMES VTAT'L'OF WESTBURY-ON-TRYM, ENGLAND, Assrenon TO J. a r. rooL,LIMITED, or rrnynn, ENGLAND. r

ROTARY SCREENIN APPARATUS.

Application filed February 4, 1928, Serial No. 251,951, and in GreatBritain February 12, 1927 The "ivention relates to rotary separators orscreens of the type in which the rotary screen g member divided up intoa series of sepruate compartments extending longitudinally from our. oend thereof, and in which each compartment is divided up into a nun'rberof sections or portions with the perforations or openings in thesuccessive sections or portions increasing in size as the 3 exit end ofthe rotary member is approached;

The object the present invention is to provide improved rotary screeningapparatus of this type in which a quick output is Ob. tained and inwhich the finest material will 5 .allpass out through the finest screen.A further object of the invention is to provide an apparatus in whichthe central shaft is suiticiently stifi" to avoid thenecessity of anybearing bet-ween its ends. I

According to the present invention there are employed a plurality ofcompartments each consisting of screens of circular cross section andprovided with perforations of successively increasing'size mounted inalignment and arranged around a common axis.

The central shaft for carrying the screens is preferably formed by anumber of arcuate plates having their concavesides outwards,

which are connected together along their outer edges, thereby forming astrong shaft which is adapted to receive the screens located partlywithin each arcuate plate. The central shaft may however be of anydesired scction.

'The hollow shaft when made of arcuate plates in the manner stated, maybe strengtlr ened by employing strips of metal or girders between eachtwo adjacentplates where they are connected together. The central shaftis 40 preferably provided with arcuate plates in planes transverse tothe central shaft and attached thereto which form seatings for thescreens.

The various portions of each screen are at- 4:5 tached to the centralshaft and preferably by means of metal straps passing around porions ofthe screens and bolted at their ends to the ends of the arcuate seatingscarried by the central shaft. The inlet ends of the finest screens mayeach be located within a ring attached to an end plate, which latter issuitably perforated to allow the material to enter the screens.

The arcuate seatings for the screens divide the exterior surface of thecentral shaftinto sections, thereby preventing the materials, which havepassed through one set of the screens on to the external surface of theshaft,

passing down beyond the junction between the said set of screens and.the adjoining coarser screens. 'lflVhen employing a central hollowshaftmade of arcuate plates connected along their edges theouter'surfaces ofthe plates forming the hollow shaft are, when desired,protected with renewable plates.

The whole group of screens is so mounted that it may be rotated upon theaxis .ofth'e central shaft, and this latter may be provided with a shortshaft and bearing at one end and a suitable bearing surface at the otherend around the entrance to the receiving chamber so I and rollers tocarry the bearing surface. The

apparatus may if desired be mounted in flexible supports such as chains,and may bero tated therein in known manner and this construction isthereforenot illustrated.

In some cases the central shaft extends slightly beyond the coarsestseries of screens and is provided withadisc or plate to arrestand'deliver the material which has been rejected by all the screens. I!i The invention is illustrated-in the accompanying drawings in whichFig. 1 is a side elevation of a complete apparatus, partly broken awayand partly in section, showing one method of carrying the invention intoeffect.

Fig. 2 is a section on theline A 13 of 'Fi I 1, so1ne details beingomitted.

Fig. 3 is an elevation of the inlet' end of the apparatus,'the screensbeing merely indicated by circles.

Fig. 4 is a section on the line CD of Fig. 1, seen in the direction ofthe arrow, some parts being omitted as hereinafter explained.

F1g. 5 1s a vert cal section taken through the end of an inlet screen ontheline EF of Fig. 4.

Fig. 6 is an end elevation partly in section on the line IJ of Fig. 8,showing a modified construction of apparatus. v j

Flg. 7 1s a section on the line G ll of Fi 6 showmg Some Parts inelevation.

Fig. 8 is a side elevation partly in section of the parts of one end ofthe screening-ap paratus shown in Figs. 6 and 7 Fig. 9 is an endelevation, partly broken away, of the parts shown in Fig. 8.

designated generallv by the Figure 4.

1,2 and 8, of circular cross section mounted in alignment, as shown. Thescreens are arranged in sets of tour around a hollow shalt It will beunderstood that other numbers of screens may be employed in sets and theshaft maybe of any suitable cross section.

lt-desired the inlet screens 1, l may each be surrounded by a perforatedjacket 5 forming an extra outer screen. The outer screen 5 has I thesmallest apertures therein, the screens 1, 1

have the next larger size oi'apertures, the screens 2, 2 have stilllarger apertures and the screens 3, 3 have the largest apertures.

rials which are retained by the screens 2 enter All these apertures aremarked 6.

The hollow shaft 4, as shown, consists of arcuate plates 7-connectedtogether at their ed e's, and in the particular construction shown'theseedges are strengthened byinner plates or girders 8, the plates 7 andgirders 8 being riveted together. Should there be any other number ofscreens than four in a set the hollowshaft will be'made of a like'numbero'lt'arcuate plates. f

To the outer-concave sides'of the plates 7 are fixed the angle plates 9,shown inFigs. '1 and 12'but omitted in 4 for the 'sakeot' clea'rnessjforfixing the arcuate flanged plates 10 which form seatings for the screens1., 2, 3. These screens 1,2,8 intermediate of their ends are fixed uponthe 'seati'ngs' 10 by means of straps 11. The straps 11 and plates 10have radial projections which are connected by nuts and bolts 12. v 7

'At their inlet ends the screens 1 are tastened by bands 13 which fitaroundthe screens 1 and around fianged rings 14 which are fixed to aplate 15 having apertures 16 formed therein for the admission of thematerials to be screened'intc the screens 1, 1. The plate 15 is providedwith a cone 17, the two parts being'fixe'd together by T plates 18. Tothe cone 17 is fixed an end plate 19having a central aperture: 20through whichthe materials are fed. The endplate '19 carries an outerrim 21'which is supported by rollers 22 mounted in suitable bearings andsupports 23.

Theouter screen 5,5 are supported at one end by the screens 1 bymeans ofthe distance ieces 24 which are bolted to the screens 1 and at the otherend by'me'ans of a distance ring 25. Divided rings 26 are employedaround the distance pieces'24 and distance i rings 25 to secure thescreens 5 to the inner screens 1. I

The'hollow shaft 4-is connected atthe outlet end of the apparatus to aclosing plate 27 carrying a bevel wheel 28. Within the clos-' ing plateand bevel wheel 28 there is fixed a 01 olefi- 09 i; l be no 00 s oru sla a moun ed ma carin a car ried by a suitable support 31. As seen inFig. 2 the bevel wheel 28 is driven by a bevel pinion 32 which ismounted upon a shaft 33. The bevel pinion 32 and shaft 33 are omitted inFig. 1.

The materials to be screened through the aperture 20 in the end plate1.9 into the cone 1? and find their way through the apertures 16directly into the screens 1. The finer materials escape from thescreens-1 are fed into the outer screens 5 from which thefinestmaterials escape through the apertures therein. The coarsermaterials which find their way into the outer screens 5 are delivered atthe ends 34.

V The materials which air retained by the screens 1 then pass into thescreens 2 and pass through the apertures therein. The matethe'screens 3and part thereof passes out through the apertures in these lastmentioned screens. The'remaining and larger portions of material passout of the screens 8 at the ends 35 thereof.

The materials which pass through the apertures in the screens and whichmay rest through part of a revolution in the concave portions of thehollowshattt 4, cannot pass the plates or seat-ings 10, and'cannot'theretore get mixed with the material passing through the nextcoarser screens.

@n the plates 7 and intermediate ofthe seatings 10 may be arranged thinplates 36,

which can be readily renewed', to protect th'e plates 7. These plates 36are shown'in Figs. 1 and 4. V i

The modified'iorrn ofapparatus shown in Figs. 6, 7, 8 and 9 allows eachscreen 3 to be rotated upon its own axis whilst rotatingtogcther withthe hollow shaft 4. This modified apparatus also allows all the screensto receive a reciprocating longitudinal movement.

The screens have each fixed around its exterior a roller pathS'? whichis'c'arried" by rollers 38 mounted in a channel ring 39which is fixed tothe hollow shaft 4. These rollers 38 not only allow the screens 3 torotate upon their own axes but allow them to slide loncarried bybrackets 44 fixed to the hollow shaft 4. As the screens 3 rotate ontheir own axes the cams 42 will be acted upon by the cam rollers 43 andthe screens 3 will be moved longitudinally in one direction.

Each screen 3 is provided in ts interior with a cross piece'45, throughwhich passes one end of a spring 46. The other end of the spring 46passes through the closing plate 27 of the hollow shaft 4. When thescreens, shown in Figs. 7 and 8, havebeen moved to the right by theaction of the rollers 43 and cams 42, the springs 46 will return theparts towards the left after the rollers leave the cam surfaces. Theends of the springs 46 can rotate in the plates 27 and in the crosspieces 45, thereby allowing the screens '3 'to rotate with respect tothe 1101 low shaft.

Any ordinary means may be employed to decrease friction between the endsof the spring 46 and the parts 27 and 45.

It will be understood that if the'cams '42 and cam rollers 43 be omittedthat the screens 3 will only receive a rotary movement upon their ownaxes in addition to the rotary move ments of the hollow shaft 4.

In the modification shown in Figs. 10 and 11 the screens 3 are providedwith exterior roller paths 37 and are carried by rollers 38 and channelrings 39, as previously described, but are not provided with gear wheels40 and there is no external gear wheel 41.

On the ends of the screens 3 are fixed brackets 47 carr in cam rollers48 which' as the shaft 4 rotates, are engaged by the cams 49 on thestationary rings 50 which move the screens 3 to the right. These screens3 are returned to the left by springs 46 as previously described. Inthis construction the screens 3 merely receive a reciprocating motion inaddition to the rotary motion imparted by the shaft 4.

What I claim as my invention is 1. An improved rotary screeningapparatus having a plurality of compartments each consisting of screensof circular cross section mounted in alignment and provided withperforations of successively increasing size, a

' perforations of successively increasing size,

a central shaft around which the screens are fixed, said central shaftbeing formed by a number of arcuate plates having their concaveside's'outwards, which are" connected along their outer edges,'.stripsof metal fixed between the edges of each two adjacent plates, means fordelivering the materials to be screened directly into the screens havingthe smallest perforations at one end of the compartments', and means-forsupporting and driving the screens and shaft as set forth.

3.- An improved rotary screenmg apparatus having a plurality ofcompartments each consisting of screens of circular cross sectionmounted in alignment and provided with perforations of successivelyincreasing size, a central shaft around which the screens are fixed,said centralshaft being formed by a number of arcuate plates havingtheir con cave sides outwards, which; are connected,

together along their outer edges, arcuate seat ings attached to saidarcuateplate's'and acting as seatings for the said screens, metal strapspassing around portions of the screens and bolted at. their ends to theends of the arcuate seatings, means for delivering the n, i

terials to be screened directly into the screens having the smallestperforationsat oneend of the compartments,- and means for supporting anddriving the screens and shaft as set forth. I y

4. An improved rotary screening apparatus having a plurality ofcompartments each consisting of screens of circular cross sectionmounted in alignment and provided with perforations of successivelyincreasing size, a central shaft around which the screens are fixed,outer screens surrounding the screens having the smallest apertures andsupported on said screens by means of distance pieces between thesescreens, and divided rings clamping the outer screensto the distancepieces, means for delivering the materials to be screened directly intothe screens having the smallest perforations at one end of thecompartments,- and means for shaft as set forth.

5. An improved rotary screening apparatus having a plurality ofcompartments each consisting of screens ofcircular cross section mountedin alignment and provided with perforations of successively increasingsupporting and driving the screens and size, a central shaft aroundwhich the screens are fixed, said central shaft beingformed by a numberofarcuate plates having their concave sides outwards, which areconnected along their outer edges, outer screens surround ng the screenshaving the smallest apertures, distance pieces between the inner and theouter screens, divided rings clamping the outer screens onto thedistance pieces, means for delivering the materials to be screeneddirectly into the screens having the smallest perforations at one end ofthe compartments, and means for supporting and driving the screens andshaft as set forth.

6. An improved rotary screening appasize,

ratus having a ,plurality of compartments each consisting of screens ofcircular cross section mounted .in alignment and provided withperforations ofsuccessively increasing outer screens surrounding thesaid screens having the smallest apertures, distance pieces between theinner and the outer directly into the screens having the smallestperforations at one end of the-compartments,

andtmeans for supporting and driving the screens and shaft as set forth.

7. All improved rotary screening apparatus having a ,plurality ofcompartments veach consisting of screens of circular cross sectionmounted in alignment and provided with perforations of successivelyincreasing S1Z6,O 1l1l61 screens surrounding the screens havlng thesmallest apertures, 'dlstance pleces between the inner and theoutervscreens, di- 7 vided rings clainpingthe outer screens on to thedistance pieces, a central shaft around which the screens are fixed,said central shaft being formed 'bya numberof arcuate plates havingtheir concave sides outwards, which are connected together along theirouter edges, arcuateseatings attached to said arenate platesand actingasseatings for the said screens, metal strapspassingaround portions of thescreens and bolted at theirends to the ends of the arcuate seatings,means for delivering the materials to be screened directly into thescreens having the smallest perforations'at one iend of thecompartments, and means for supporting and drivingthe screens and shaftas set forth.

In witness whereof I have hereunto set my hand.

JAMES WATT.

